Structure-activity relationships in platelet-activating factor (PAF).7. Tetrahydrofuran derivatives as dual PAF antagonists and acetylcholinesterase inhibitors. Synthesis and PAF-antagonist activity

in Journal of Lipid Mediators and Cell Signalling (1996), 13

Structure-Activity Relationships in the Beta-Lactam Family: An Impossible Dream

in Biochemical Pharmacology (1988), 37(1), 125-32

The difficulty of establishing structure-activity relationships in the beta-lactam family of antibiotics stems from the fact that: (1) The targets in various bacteria exhibit widely different ... [more ▼]

The difficulty of establishing structure-activity relationships in the beta-lactam family of antibiotics stems from the fact that: (1) The targets in various bacteria exhibit widely different sensitivities. (2) Some bacteria produce beta-lactamases, enzymes capable of destroying the antibiotics. The rates of the reactions with the beta-lactamases and the target enzymes are not necessarily related. (3) In Gram-negative bacteria, the diffusion rate through the outer membrane varies independently from the two other factors. [less ▲]

Structure-activity relationships on adrenoceptors and imidazoline-preferring binding sites (I(1,2)-PBSs). Part 1: Weak intramolecular H-bond and conformational flexibility in a new I1-PBS-selective imidazoline analogue, trans1-(4',5'-dihydro-1'H-imidazol-2'-yl)methyl-2-hydroxyindane (PMS 952).

in Bioorganic & Medicinal Chemistry (2000), 8(8), 1861-9

The highly selective I1-PBS imidazoline analogue PMS 952 has been selected to study the incidence of intramolecular hydrogen bond and molecular flexibility on its biological activity. On one hand, the ... [more ▼]

The highly selective I1-PBS imidazoline analogue PMS 952 has been selected to study the incidence of intramolecular hydrogen bond and molecular flexibility on its biological activity. On one hand, the weak energy difference between three calculated conformers does not support the stabilization of one conformer by an internal hydrogen bond. The 3-D electrostatic map confirms this feature and the solvent effect does not significantly modify the relative energy of these conformers. On the other hand, the conformational spaces of the neutral and ionized forms present a great number of equilibrium structures, in a short energetic range (20 Kcal). The results are representative of an exceptional conformational flexibility due to a cooperative effect between several parts of the molecule. [less ▲]

Structure-based design of selective high-affinity telomeric quadruplex-binding ligands

in Chemical Communications (2010), 46

A library of triazole-based telomeric quadruplex-selective ligands has been developed that mimic an established family of tri-substituted acridine-based ligands, using crystal structure data as a starting ... [more ▼]

A library of triazole-based telomeric quadruplex-selective ligands has been developed that mimic an established family of tri-substituted acridine-based ligands, using crystal structure data as a starting-point for computer-based design. Binding affinities, estimated by electrospray mass spectrometry, are in accord with the design concept [less ▲]

. Structure-function analysis of amyloid peptide and prion protein by molecular modeling

Conference (1997, May)

Structure-function analysis of amyloid peptide and prion protein by molecular modeling : prediction and demonstration of tilted fusogenic fragments

Conference (1997, March)

Structure-Guided Design of Cell Wall Biosynthesis Inhibitors That Overcome beta-Lactam Resistance in Staphylococcus aureus (MRSA).

in ACS Chemical Biology (2011)

beta-Lactam antibiotics have long been a treatment of choice for bacterial infections since they bind irreversibly to Penicillin-Binding Proteins (PBPs), enzymes that are vital for cell wall biosynthesis ... [more ▼]

beta-Lactam antibiotics have long been a treatment of choice for bacterial infections since they bind irreversibly to Penicillin-Binding Proteins (PBPs), enzymes that are vital for cell wall biosynthesis. Many pathogens express drug-insensitive PBPs rendering beta-lactams ineffective, revealing a need for new types of PBP inhibitors active against resistant strains. We have identified alkyl boronic acids that are active against pathogens including methicillin-resistant S. aureus (MRSA). The crystal structures of PBP1b complexed to 11 different alkyl boronates demonstrate that in vivo efficacy correlates with the mode of inhibitor side chain binding. Staphylococcal membrane analyses reveal that the most potent alkyl boronate targets PBP1, an autolysis system regulator, and PBP2a, a low beta-lactam affinity enzyme. This work demonstrates the potential of boronate-based PBP inhibitors for circumventing beta-lactam resistance and opens avenues for the development of novel antibiotics that target Gram-positive pathogens. [less ▲]

Structure-modifying drugs in osteoarthritis

in Osteoporosis International (2002), 13(Suppl. 1), 49-50

Structure-second-order polarizability relationship in chromophores incorporating a spacer: a joint experimental and theoretical study

in Chemistry : A European Journal (1999), 5(1), 369-380

A joint theoretical and experimental study is reported on the structure-polarizability relationship in a novel type of push-pull conjugated system which contains a spacer within the conjugated backbone ... [more ▼]

A joint theoretical and experimental study is reported on the structure-polarizability relationship in a novel type of push-pull conjugated system which contains a spacer within the conjugated backbone. The chromo-phores are based on a dithienyl conjugation pathway, spaced by a keto group, and selectively end-capped by a donor and an acceptor. Four chromophores were synthesized, in which the strength of the acceptor group and the length of the conjugated path were varied. The electronic properties of two model compounds were studied theoretically by means of correlated quantum-chemical calculations. The degree of ground-state polarization was varied in the calculations by the application of an external electric field and varied experimentally by the modification of the dielectric constant of a binary mixture of solvents. The linear and nonlinear optical properties of the compounds (measured in solution by hyper-Rayleigh scattering) are discussed in detail. [less ▲]

Structure-Surface Activity Relationships Of Uronic Acid-Derivative Surfactants From Renewable Resources Applications

Poster (2011, June)

Introduction and Background: Uronic acid-derivative surfactants are amphiphilic compounds with growing interests owing to their potential applications in various areas [1]. This class of carbohydrate ... [more ▼]

Introduction and Background: Uronic acid-derivative surfactants are amphiphilic compounds with growing interests owing to their potential applications in various areas [1]. This class of carbohydrate-based surfactants can be easily prepared from renewable raw materials in a wide range of structure by modular synthesis thanks to the presence of one carboxylic and numerous hydroxyl groups. The polar head group configurations according to the stereochemistry of OH groups, and geometry (cyclic or not), the hydrophobic tail (number and length of alkyl chain), and the type of linker (ester, acetal and amide, etc) are among the main variables in their structural entities. Therefore, the investigation of their structure-surface activity relationships appears valuable for increasing backgrounds, and achieving a rational design for selecting the best structures to be used in different industrial fields [2]. Methodology: A few analogous of glucuronic acid-derivative surfactants have been synthesized by chemical or enzymatic routes. After purification, their structure has been confirmed by various spectroscopic techniques (RMN, MS, IR). Surface tensions of true aqueous solution have been then measured in dynamic and static modes using a series of complementary techniques. Critical micelle concentrations, minimum molecular areas, and maximum surface excesses have also been determined. Results and Discussion: Glucuronic acid derivative surfactants under investigation vary in the polar head group configuration including cyclic or non-cyclic structure and α or β anomeric form, in the hydrophobic tail regarding to the chain length (C8 to C14), the presence of a double bond, as well as an OH group at the terminal carbon, and in the type of linker, ester in C6 or acetal in C1. Results showed that all of these structural attributes affect both dynamic and equilibrium surface properties of glucuronic acid -based surfactants. Conclusion: A set of synthetic glucuronic acid-based surfactants varying in the polar head group, hydrophobic tail, and linker allow us to generate various surface-active properties at the air-water interface, and to increase the knowledge on relationships between their structure and surface-active properties. [1] Laurent, P.; Razafindralambo, H.; Wathelet, B.; Blecker, C.; Wathelet, J.-P.; Paquot, M., Synthesis and Surface-Active Properties of Uronic Amide Derivatives, Surfactants from Renewable Organic Raw Materials. Journal of Surfactants and Detergents 2010, in press. [2] Razafindralambo, H.; Blecker, C.; Mezdour, S.; Deroanne, C.; Crowet, J.; Brasseur, R.; Lins, L.; Paquot, M., Impacts of the Carbonyl Group Location of Ester Bond on Interfacial Properties of Sugar-Based Surfactants: Experimental and Computational Evidences. The Journal of Physical Chemistry B 2009, 113 (26), 8872-8877. Acknowledgment: This work was supported by Belgian Walloon Region within DGTRE research project of excellence (TECHNOSE). [less ▲]